Process Evaluation of Ironmaking Using In-Flight Hydrogen Plasma Reduction of Partially Pre-reduced Iron Ore

This work evaluates a hybrid ironmaking process that combines hydrogen direct reduction with in-flight hydrogen plasma reduction of iron ore powder using a new reactor, Swin H₂⁺ . The reactor uses a non-transferred DC arc plasma torch with continuous powder injection and was tested with up to 41 kW of electrical power and 9% H₂ -Ar plasma gas. The results suggest that controlling particle residence time is a major challenge for co-current in-flight plasma reactors. As a result, the optimal level of pre-reduction for in-flight systems differs from that for molten-bath reactors. Plasma-reduced iron was found to be less susceptible to reoxidation than direct-reduced iron. However, the current reactor design experienced product losses (>90%), limited metallization (<10%), and high specific energy consumption ( ≈ 67 kWh/kg of ore, before heat recovery).